CVE-2026-53122 (GCVE-0-2026-53122)

Vulnerability from cvelistv5 – Published: 2026-06-24 16:30 – Updated: 2026-06-24 16:30
VLAI
Title
btrfs: fix deadlock between reflink and transaction commit when using flushoncommit
Summary
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix deadlock between reflink and transaction commit when using flushoncommit When using the flushoncommit mount option, we can have a deadlock between a transaction commit and a reflink operation that copied an inline extent to an offset beyond the current i_size of the destination node. The deadlock happens like this: 1) Task A clones an inline extent from inode X to an offset of inode Y that is beyond Y's current i_size. This means we copied the inline extent's data to a folio of inode Y that is beyond its EOF, using a call to copy_inline_to_page(); 2) Task B starts a transaction commit and calls btrfs_start_delalloc_flush() to flush delalloc; 3) The delalloc flushing sees the new dirty folio of inode Y and when it attempts to flush it, it ends up at extent_writepage() and sees that the offset of the folio is beyond the i_size of inode Y, so it attempts to invalidate the folio by calling folio_invalidate(), which ends up at btrfs' folio invalidate callback - btrfs_invalidate_folio(). There it tries to lock the folio's range in inode Y's extent io tree, but it blocks since it's currently locked by task A - during a reflink we lock the inodes and the source and destination ranges after flushing all delalloc and waiting for ordered extent completion - after that we don't expect to have dirty folios in the ranges, the exception is if we have to copy an inline extent's data (because the destination offset is not zero); 4) Task A then attempts to start a transaction to update the inode item, and then it's blocked since the current transaction is in the TRANS_STATE_COMMIT_START state. Therefore task A has to wait for the current transaction to become unblocked (its state >= TRANS_STATE_UNBLOCKED). So task A is waiting for the transaction commit done by task B, and the later waiting on the extent lock of inode Y that is currently held by task A. Syzbot recently reported this with the following stack traces: INFO: task kworker/u8:7:1053 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:7 state:D stack:23520 pid:1053 tgid:1053 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-btrfs-46) Call Trace: <TASK> context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 wait_extent_bit fs/btrfs/extent-io-tree.c:811 [inline] btrfs_lock_extent_bits+0x59c/0x700 fs/btrfs/extent-io-tree.c:1914 btrfs_lock_extent fs/btrfs/extent-io-tree.h:152 [inline] btrfs_invalidate_folio+0x43d/0xc40 fs/btrfs/inode.c:7704 extent_writepage fs/btrfs/extent_io.c:1852 [inline] extent_write_cache_pages fs/btrfs/extent_io.c:2580 [inline] btrfs_writepages+0x12ff/0x2440 fs/btrfs/extent_io.c:2713 do_writepages+0x32e/0x550 mm/page-writeback.c:2554 __writeback_single_inode+0x133/0x11a0 fs/fs-writeback.c:1750 writeback_sb_inodes+0x995/0x19d0 fs/fs-writeback.c:2042 wb_writeback+0x456/0xb70 fs/fs-writeback.c:2227 wb_do_writeback fs/fs-writeback.c:2374 [inline] wb_workfn+0x41a/0xf60 fs/fs-writeback.c:2414 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> INFO: task syz.4.64:6910 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.64 state:D stack:22752 pid:6910 tgid: ---truncated---
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 05a5a7621ce66c142e081ffc24dd6ade6e912061 , < 73be4a08306bb84f4d5d16f62cb80e1543109ffa (git)
Affected: 05a5a7621ce66c142e081ffc24dd6ade6e912061 , < 9a24f0000876b8755cf21972b41632f4d6f3dafb (git)
Affected: 05a5a7621ce66c142e081ffc24dd6ade6e912061 , < 6f0f9c0a368aa1fe078109091322d3b0632d9380 (git)
Affected: 05a5a7621ce66c142e081ffc24dd6ade6e912061 , < b48c980b6a7e409050bb3067165db31cc6205e3e (git)
Create a notification for this product.
Linux Linux Affected: 5.7
Unaffected: 0 , < 5.7 (semver)
Unaffected: 6.12.91 , ≤ 6.12.* (semver)
Unaffected: 6.18.33 , ≤ 6.18.* (semver)
Unaffected: 7.0.10 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/reflink.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "73be4a08306bb84f4d5d16f62cb80e1543109ffa",
              "status": "affected",
              "version": "05a5a7621ce66c142e081ffc24dd6ade6e912061",
              "versionType": "git"
            },
            {
              "lessThan": "9a24f0000876b8755cf21972b41632f4d6f3dafb",
              "status": "affected",
              "version": "05a5a7621ce66c142e081ffc24dd6ade6e912061",
              "versionType": "git"
            },
            {
              "lessThan": "6f0f9c0a368aa1fe078109091322d3b0632d9380",
              "status": "affected",
              "version": "05a5a7621ce66c142e081ffc24dd6ade6e912061",
              "versionType": "git"
            },
            {
              "lessThan": "b48c980b6a7e409050bb3067165db31cc6205e3e",
              "status": "affected",
              "version": "05a5a7621ce66c142e081ffc24dd6ade6e912061",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/reflink.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.7"
            },
            {
              "lessThan": "5.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.91",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.33",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.91",
                  "versionStartIncluding": "5.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.33",
                  "versionStartIncluding": "5.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.10",
                  "versionStartIncluding": "5.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "5.7",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix deadlock between reflink and transaction commit when using flushoncommit\n\nWhen using the flushoncommit mount option, we can have a deadlock between\na transaction commit and a reflink operation that copied an inline extent\nto an offset beyond the current i_size of the destination node.\n\nThe deadlock happens like this:\n\n1) Task A clones an inline extent from inode X to an offset of inode Y\n   that is beyond Y\u0027s current i_size. This means we copied the inline\n   extent\u0027s data to a folio of inode Y that is beyond its EOF, using a\n   call to copy_inline_to_page();\n\n2) Task B starts a transaction commit and calls\n   btrfs_start_delalloc_flush() to flush delalloc;\n\n3) The delalloc flushing sees the new dirty folio of inode Y and when it\n   attempts to flush it, it ends up at extent_writepage() and sees that\n   the offset of the folio is beyond the i_size of inode Y, so it attempts\n   to invalidate the folio by calling folio_invalidate(), which ends up at\n   btrfs\u0027 folio invalidate callback - btrfs_invalidate_folio(). There it\n   tries to lock the folio\u0027s range in inode Y\u0027s extent io tree, but it\n   blocks since it\u0027s currently locked by task A - during a reflink we lock\n   the inodes and the source and destination ranges after flushing all\n   delalloc and waiting for ordered extent completion - after that we\n   don\u0027t expect to have dirty folios in the ranges, the exception is if\n   we have to copy an inline extent\u0027s data (because the destination offset\n   is not zero);\n\n4) Task A then attempts to start a transaction to update the inode item,\n   and then it\u0027s blocked since the current transaction is in the\n   TRANS_STATE_COMMIT_START state. Therefore task A has to wait for the\n   current transaction to become unblocked (its state \u003e=\n   TRANS_STATE_UNBLOCKED).\n\n   So task A is waiting for the transaction commit done by task B, and\n   the later waiting on the extent lock of inode Y that is currently\n   held by task A.\n\nSyzbot recently reported this with the following stack traces:\n\n  INFO: task kworker/u8:7:1053 blocked for more than 143 seconds.\n        Not tainted syzkaller #0\n  \"echo 0 \u003e /proc/sys/kernel/hung_task_timeout_secs\" disables this message.\n  task:kworker/u8:7    state:D stack:23520 pid:1053  tgid:1053  ppid:2      task_flags:0x4208060 flags:0x00080000\n  Workqueue: writeback wb_workfn (flush-btrfs-46)\n  Call Trace:\n   \u003cTASK\u003e\n   context_switch kernel/sched/core.c:5298 [inline]\n   __schedule+0x1553/0x5240 kernel/sched/core.c:6911\n   __schedule_loop kernel/sched/core.c:6993 [inline]\n   schedule+0x164/0x360 kernel/sched/core.c:7008\n   wait_extent_bit fs/btrfs/extent-io-tree.c:811 [inline]\n   btrfs_lock_extent_bits+0x59c/0x700 fs/btrfs/extent-io-tree.c:1914\n   btrfs_lock_extent fs/btrfs/extent-io-tree.h:152 [inline]\n   btrfs_invalidate_folio+0x43d/0xc40 fs/btrfs/inode.c:7704\n   extent_writepage fs/btrfs/extent_io.c:1852 [inline]\n   extent_write_cache_pages fs/btrfs/extent_io.c:2580 [inline]\n   btrfs_writepages+0x12ff/0x2440 fs/btrfs/extent_io.c:2713\n   do_writepages+0x32e/0x550 mm/page-writeback.c:2554\n   __writeback_single_inode+0x133/0x11a0 fs/fs-writeback.c:1750\n   writeback_sb_inodes+0x995/0x19d0 fs/fs-writeback.c:2042\n   wb_writeback+0x456/0xb70 fs/fs-writeback.c:2227\n   wb_do_writeback fs/fs-writeback.c:2374 [inline]\n   wb_workfn+0x41a/0xf60 fs/fs-writeback.c:2414\n   process_one_work kernel/workqueue.c:3276 [inline]\n   process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359\n   worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440\n   kthread+0x388/0x470 kernel/kthread.c:436\n   ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158\n   ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n   \u003c/TASK\u003e\n  INFO: task syz.4.64:6910 blocked for more than 143 seconds.\n        Not tainted syzkaller #0\n  \"echo 0 \u003e /proc/sys/kernel/hung_task_timeout_secs\" disables this message.\n  task:syz.4.64        state:D stack:22752 pid:6910  tgid:\n---truncated---"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-24T16:30:51.941Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/73be4a08306bb84f4d5d16f62cb80e1543109ffa"
        },
        {
          "url": "https://git.kernel.org/stable/c/9a24f0000876b8755cf21972b41632f4d6f3dafb"
        },
        {
          "url": "https://git.kernel.org/stable/c/6f0f9c0a368aa1fe078109091322d3b0632d9380"
        },
        {
          "url": "https://git.kernel.org/stable/c/b48c980b6a7e409050bb3067165db31cc6205e3e"
        }
      ],
      "title": "btrfs: fix deadlock between reflink and transaction commit when using flushoncommit",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-53122",
    "datePublished": "2026-06-24T16:30:51.941Z",
    "dateReserved": "2026-06-09T07:44:35.386Z",
    "dateUpdated": "2026-06-24T16:30:51.941Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.